Skin cancer patients often have tumorigenic lesions on their noses. Surgical resection of the lesions often results in nasal cartilage removal. Cartilage grafts taken from other anatomical sites are used for the surgical reconstruction of the nasal cartilage, but donor‐site morbidity is a common problem. Autologous tissue‐engineered nasal cartilage grafts can mitigate the problem, but commercially available scaffolds define the shape and sizes of the engineered grafts during tissue fabrication. Moreover, the engineered grafts suffer from the inhomogeneous distribution of the functional matrix of cartilage. Advances in 3D bioprinting technology offer the opportunity to engineer cartilages with customizable dimensions and anatomically shaped configurations without the inhomogeneous distribution of cartilage matrix. Here, we report the fidelity of Freeform Reversible Embedding of Suspended Hydrogel (FRESH) bioprinting as a strategy to generate customizable and homogenously distributed functional cartilage matrix engineered nasal cartilage. Using FRESH and in vitro chondrogenesis, we have fabricated tissue‐engineered nasal cartilage from combining bovine type I collagen hydrogel and human nasoseptal chondrocytes. The engineered nasal cartilage constructs displayed molecular, biochemical and histological characteristics akin to native human nasal cartilage.

The purpose of the study is to compare alkaloid profile of Uncaria rhynchophylla hooks and leaves. Ten oxindole alkaloids and four glycosidic indole alkaloids were identified using HPLC-diode array detection (DAD) or LC-atmospheric pressure chemical ionization (APCI)-MS method, and a HPLC-UV method for simultaneous quantification of major alkaloids was validated. The hooks are characterized by high levels of four oxindole alkaloids rhynchophylline (R), isorhynchophylline (IR), corynoxeine (C) and isocorynoxeine (IC), while the leaves contained high level of two glycosidic indole alkaloids vincoside lactam (VL) and strictosidine (S). The presented methods have proven its usefulness in chemical characterization of U. rhynchophylla hooks and leaves.Key words oxindole alkaloid; glycosidic alkaloid; Uncaria rhynchophylla; alkaloid profile; HPLC; LCatmospheric pressure chemical ionization-MS China has an abundant resource of Uncaria rhynchophylla (MIQ.) JACKS. The hooks on this plant are used in the treatment of infantile convulsion, headache, dizziness, hypertension and stroke in Traditional Chinese Medicine and Japanese Kampo Medicine. 1,2) In addition, the leaves, as a candidate part of the hooks, 3) are used in the manufacture of an antihypertensive remedy in China. 4) Oxindole alkaloids such as rhynchophylline (R) and isorhynchophylline (IR) are major components of U. rhynchophylla, 5) responsible for the cardiocerebral vascular effects, including hypotension, 6) vasodilation, 7) anti-platelet aggregation 8) and protective effect against neuronal damage. 9)Concerning quality assessment of U. rhynchophylla hooks, HPLC-UV method may be practical for determination of oxindole alkaloids due to the characteristic absorption of indole ring at 245 nm and 290 nm.10) The alkaloid profile of the hooks was studied using HPLC-UV technique in the previous literatures.11) LC-MS technique is able to provide both analytical separation and structural determination of unknown bioactive compounds, which was applied to chemically characterize the oxindole alkaloids from Uncaria tormentosa 12) and the metabolites of R and IR. 13,14) Yamanaka et al. determined ten tertiary alkaloids in various parts of U. rhynchophylla, indicating that the alkaloid profile of the leaves is similar to that of the hooks.15) Recently, we reported the isolation of several oxindole alkaloids and glycosidic indole alkaloids from U. rhynchophylla leaves, together with their inhibitory effects on microglial activation. R, IR, corynoxeine (C), isocorynoxeine (IC), strictosidine (S) and vincoside lactam (VL) are found to be potently active. [16][17][18] However, the chemical analysis of S and VL of U. rhynchophylla has not been reported yet.In the present study, ten oxindole alkaloids and four glycosidic alkaloids from U. rhynchophylla hooks and leaves were identified by HPLC-diode array detection (DAD) and LC-MS technologies. Moreover, an accurate and sufficiently sensitive HPLC-UV method was validated to simultaneously determine these alkaloids. Utilizing opt...

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Injectable bone cements have been well characterized and studied in non-load bearing bone fixation and bone screw augmentation applications. Current calcium phosphate cement or poly(methyl methacrylate) cement have drawbacks like low mechanical strength and in situ exothermic properties. This leads especially in patients with osteoporosis to worsening contact between implant and bone and can finally lead to implant failure. To improve these properties, a calcium silicate cement (CSC) was prepared, which additionally contained the bisphosphonate risedronate (RA) to promote osteoblast function. Cement setting rate and compressive strength were measured and found to be reduced by RA above 0.5 wt%. X-ray diffraction, Rietveld refinement analysis, scanning electron microscopy, and porosity measurements by gas sorption revealed that RA reduces calcium silicate hydrate gel formation and changes the cement's microstructure. Cumulative release profiles of RA from CSC up to 6 months into phosphate buffer solution were analyzed by high-performance liquid chromatography, and the results were compared with theoretical release curves obtained from the Higuchi equation. Fourier transform infrared spectra measurements and drug release studies indicate that calcium-RA formed within the cement, from which the drug can be slowly released over time. An investigation of the cytotoxicity of the RA-CSC systems upon osteoblast-like cells showed no toxic effects of concentrations up to 2%. The delivery of RA from within a CSC might thus be a valuable and biocompatible new approach to locally deliver RA and to reconstruct and/or repair osteoporosis-related bone fractures.

Vertebral compression fractures can be successfully restored by injectable bone cements. Here the as-yet unexplored in vitro cytotoxicity, in vivo biodegradation, and osteoconductivity of a new calcium phosphate silicate cements (CPSC) are studied, where monocalcium phosphate (MCP; 5, 10, and 15 wt%) is added to calcium silicate cement (CSC). Setting rate and compressive strength of CPSC decrease with the addition of MCP. The crystallinity, microstructure, and porosity of hardened CPSC are evaluated by X-ray diffractometer, Fourier transform infrared spectroscopy, and microcomputed tomography (CT). It is found that MCP reacts with calcium hydroxide, one of CSC hydration products, to precipitate apatite. While the reaction accelerates the hydration of CSC, the formation of calcium silicate hydrate gel is disturbed and highly porous microstructures form, resulting in weaker compressive strength. In vitro studies demonstrate that CPSC is noncytotoxic to osteoblast cells and promotes their proliferation. In the rabbit tibia implantation model, clinical X-ray and CT scans demonstrate that CPSC biodegrades slower and osseointegrates better than clinically used calcium phosphate cement (CPC). Histological studies demonstrate that CPSC is osteoconductive and induces higher bone formation than CPC, a finding that might warrant future clinical studies.